Cable extension sleeve



Feb. 21, 1961 w. L. MlNTZ EIAL 3,972,492

CABLE EXTENSION SLEEVE Filed Oct. 13, 1958 MFPED l. AIM/r2 1905527 {Z MONTGOMEE) JNVENTORS.

United States PatentjO CABLE EXTENSION SLEEVE Wilfred L. Mintz, Granada Hills, and Robert J. Montgomery, San Fernando, Calif., assignors, by mesne assignments, to Glenair, Inc., Glendale, Calif., a corporation of California Filed Oct. 13, 1958, Ser. No. 766,950

4 Claims. (Cl. 285-117) I The present invention relates to a cable extension sleeve, a clamp adapter blank, and a method of making the cable extension sleeve having a cable clamp adjustably mounted thereon whereby a standardized pair of such blanks may be used in making such clamps for use with cables having different external diameters.

Multiconductor cables used at the present time in aircraft, rocket and missile fields as well as many other electronic devices are desirably made in relatively short lengths and such lengths are coupled together by the use .of connectors involving a male element and a female element. Each conductor of a cable is soldered or otherwise connected to a pin in the male element; these pins slidably' enter sockets in a female element at the connector, each socket being in'electrical contact with a conductor in another section of cable. These conductor elements are separably connected and a cable can betherefore lengthened or shortened and selectively connected to different units or pieces of equipment by the use of such readily separable connectors without laborious splicing, soldering, confusion as to identity of individual conductors, etc. 1 These multiconductor cables may contain 20, 30 or even 50 individual conductors whose ends need be soldered torthe pins of a connector. The cables are ordinarily provided with a flexible neoprene or other composition jacket, the cable being tightly clamped and held by an encircling clamp about 1" away from the end of the cable and the short 1" portion of the jacket stripped away to expose the conductors, the clamp preventing longitudinal splitting of the jacket, fraying of the insulation and longitudinal displacement of individual conductors. The soldering of these extremely short, closely adjacent conductorends to their respective pins or sockets of a connector in a limited space has been a tedious, time-consuming, vexatious and delicate operation. So-called back-shells have been used between the pin face of a connector and the clamp, but these have not been satisfactory. In many cases the same connector has been used with cables of sizes differing as much as from /z" to 2" in diameter; as a result, it has been necessary to provide a large number of clamps, each for a cable of a difierent diameter and an equal number and variety of back-shells. Stock inventory and manufacturing problems, high costs and high incidence of mistakes resulted from such prior attempts.

The present invention eliminates prior disadvantages and provides an extension sleeve which performs a number of functions: it cooperates with a clamp and posi tively centers the clamp about a cable; it holds the clamp and cable in a desired position with respect to the sleeve; it is provided with means for releasably connecting the sleeve to a connector; it provides an enlarged and elongated area in which the individual conductor wires can be separated, stripped, classified and soldered; it provides a receptacle forlatex putty or synthetic rubber composition which insulates the individual conductors andmainthem in suitable spaced relation and bonds to the j insulation and jacket of the multiconductor cable. Furconnector.

Another object is to provide a method of making an extension sleeve for assembling cables of varying diameters to an electrical connector which is less expensive and simpler than any other method used heretofore.

A further object of the invention is the provision of a novel clamp adapter blank.

Still another object is to provide a clamp adapter blank which can be used in the method of making clamps for the extension sleeve of the present invention and which will eliminate the high cost of manufacturing and main- 2 of a preferred embodiment of a cable extension sleeve,-

taining a plurality of different size clamps for connecting varying diameter cables to a standard size electrical connection.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: a h

Fig. 1 shows a side elevation, with parts cut away,

made by the method of the presentinventicn, connecting a cable to an electrical connector.

Fig. 2 illustrates a plan view of a clamp adapter blank of the present invention.

Fig. 3 is a side elevation of the clamp adapter blank shown in Fig. 2.

Fig. 4 shows a pair of clamp adapter blanks mounted on the rear end of the extension sleeve body and separated by spacers in a pre-dri'lling position.

Fig. 5 illustrates the clamp adapter blanks in the same position as shown in Fig. 4 but a hole has been drilled through the blanks to form a clamp having a pair of spaced cable-grasping, arcuate surfaces.

Fig. 6 shows the clamp after being drilled, the'spacers removed and in a closed, clamping position with a cable.

Fig. 7 is a transverse section of the device taken along plane VIIVII of Fig. 6.

Fig. 8 illustrates a pair of clamp adapter blanks in a. position similar to that shown in Fig. 6 but having been drilled to forma clamp having a pair of spaced cablegrasping, arcuate surfaces for clamping a cable having a diameter smaller than that shown in Fig. 6.

A completely assembled cable connector assembly isillustrated in Fig. 1 and comprises the multiconductor cable 10, the novel clamp 20 of this invention, cooperatively attached to one end of exemplary extension sleeve 40, and a male connector 50 attached to the other end of the extension sleeve. The outer jacket 11 of the cable is tightly grasped by the clamp 20; the individual conductors 12 and 12 with their individual insulation 13 and 13' are shown splayed within the tubular extension sleeve 40, each end of a conductor being soldered or otherwise electrically connected to a contact pin such as 52 and 5250f the connector 50. The entire interior of the extension sleeve 40 may be filled (as through port.41) with a selfc'uring or self-setting synthetic rubber composition (not shown) having dielectric characteristics to suitablycover, embed and protect thev conductors 12, 12', etc. The. means for connecting the sleeve 40 to connector 50 are illustrated as threads 42, and locking set screw'43, a1

Patented Feb. 21, 1961.

though other means, such as bayonet type connections may be used.

It may be noted that the tubular extension sleeve 40 has one open end (into which the connector 511 is attached) and one partly closed endhaying the endw'all 45 provided with an axial port 44 (Fig. 7). end wall 45 carries, as an integral part thereof, a pair ofdiametrically positioned T-shaped centeringand clamp supporting members 46 and 46'- in parallel relation to each other and the axis of the tubular extension sleeve 40. Eaeh T-shaped member 46 and 46 includes oppositely directed arms 47 and 47 respectively, the arm 47 of supporting. member 46 lying in a plane parallel to, opposing and spaced from arm 47 of supporting member 46. The shank of each T-shaped member is provided with a through bore 48. The importance and function of' these supporting members will become apparent from subsequent description.

The clamp 20 is designed to fit and cooperate with extension sleeves which may differ in diameter and length and to firmly grasp cables difiering in diameter. The clamp is made of two identical blanks, one of which is illustrated in Figs. 2 and 3. Each blank (made of any suitable metal, alloy or composition) has a planar front face 21, bounded by longitudinal sides 22 and 22 and transverse end planes 23 and 23'. An integral car 24 (and 24') extends from each end of the blank. Each ear or lug 24 has a front face 25 lying in a plane spaced from but parallel to the front face 21 of the blank. A transversely extending guiding and centering slotor groove 26 (and 26") is formed in each ear 24 adjacent the transverse end plane 23. The bottom 27 of each slot or groove is spaced from and below the front face 25- of each ear. The back or rear face of each blank may be parallel to the front face; in the form shown such back face is convexly curved as at 28 with planar end portions at the ears, such planar portions being parallel to the front faces 25 of the cars. It will be seen that each blank is symmetrical about a median transverse plane. Each car may be provided with a through bore 29 having an axis perpendicular to the front faces 21 and 25; one ear bore 29 of each blank may be internally threaded and the other car bore 29 unthreaded and slightly larger in diameter.

Each blank may. also be provided with a cavity or recess 30 opening onto the front face 21 and having a bottom 31 which desirably conforms in curvature to but is spaced from the rear face 28 of the blank. Blanks as herein described may beeconomically made by die castmg. I

A pair of the above-described blanks with their front faces 21 facing each other may be placed on the end of an extension sleeve 40, and the arms 47 of the T-shaped guiding, centering and supporting members 46 will slidingly abut transverse planes-23 of the blanks and may partly extend into grooves 26 of such blanks. The blanks can be moved toward and away from each other-fin a horizontal direction in Fig. 4) but vertical motion is limited by the arms of the T-shaped members.

When it is desired to assemble a cable on the rear end of a connector 50, a pair of clamp adapter blanks are adjustably mounted on the T-shaped supporting members 46 and 46' by means of elongated bolts 60 and 60. The blanks are positioned with their planar front faces 21 facing but spaced from each other by means of spacer sleeves 61 and 61 provided on either side of the T-shaped supporting members 46 and 46'. As seen in Fig. 4, the blanks face each other so that the threaded bore 29 in oneblank is in alignment with the unthreaded bore 29 in the other blank, and the longitudinal axis of the extension sleeve passes through the plane of symmetry of the blanks. The bolts 60 can therefore pass through the unthreaded opening 2? in one blank, the spacers 61, the T shaped supporting member 46 and be threadedly received within the threaded opening"2 9 in the other blank. The bolts 60 are then tightened to draw the blanks de -e a spaced elatio sh n a i'tlfi ll l io as shown in Fig. 4. It should be noted that the space between the planar front faces 21 of the blanks can be varied dependent upon the diameter of the cable to be assembled by merely using spacer sleeves 61 of different thicknesses.

In the pro-drilling position shown in Fig. 4, any suitable means can be used to concurrently drill, along the axis of the cable extension sleeve, 2. pairof spaced cablegrasping, arcuate surfaces 33 and 33 in the planar front faces 21 of the spaced blanks, the diameter of such arcuate surfaces being correlated to the diameter of the selected cable to be assembled to the connector 50. Fig. 5 illustrates the completed clamp 20 formed after the drilling operation and after the arcuate surfaces 33 and 33' have been formed in the blanks. It should be noted that the blanks were spaced a sufficient distance so that after drilling, a cable-gripping groove is provided in the arcuate surfaces of each portion of clamp 20, the grooves being formed out of the cavities 30 and each groove having a bottom 31.

After drilling, the spacers 61 and 61 are removed and the clamp 20 is adjustably repositioned on the T-shaped supporting members 46 and 46'. In this position, a cable extension sleeve is provided having a clamp 20 adjustably mounted thereon and adapted to receive and tightly clamp a cable having a predetermined diameter between the cable-grasping, arcuate surfaces 33 and 33' of the clamp.

As seen in Fig. 6, the cable 10 passes through the clamp 20, and within the sleeve 40 to enable the conductors 12 and 12' to be soldered to their respective connector pins. After the soldering operation, the clamp 20 is drawn tightly together by means of the bolts 60 and 60' to firmly engage the faces of the arcuate surfaces 33 and 33' with the outer jacket on the cable 10. 3 However, even in this position, it can be seen that the ends of the arcuate clamping surfaces 33 and 33' do not meet, but are spaced from each other. This will always occur regardless of how tight the clamp 20 is drawn as it can be seen that the ears 24 and 24 of the clamp 20 are in engagement with the T-shaped members 46 and 46', thus preventing further inward movement 'of the arcuate surfaces 33 and 33'.

It has been found that by providing an elliptical cable gripping surface for the clamp 20, a more secure and better gripping action is provided. noted that the arcuate surfaces 33 and 33' are elliptical and not circular when the clamp has been drawn together by means of the locking and adjusting means 60.

In this clamped position it can be seen in Fig. 7 that the material of the cable jacket is formed into the gripping grooves forming a circumferential bulge or locking shoulder 15 for preventing the cable from moving axially and damaging or exerting undue strain on the soldered connections between the conductors 12 and the pins 13.

It should be understood that any diameter opening or bore may be drilled through the clamp adapter blanks when positioned in the pre-drilling position shown in Fig. 4. The diameter of the opening to be drilled will be correlated to the outside diameter of the selected cable to be connected to the electrical connector 50. As seen in Fig. 8, a clamp 20a is adjustably mounted on the rear end of the extension sleeve 40 and is in a clamped position with a cable 10a of smaller diameter than cable 10 shown in Fig. 6. This illustrates that a smaller opening was drilled through a pair of standard clamp adapter blanks to form arcuate surfaces 33a and 33a having smaller radii. to conform to the smaller diameter cable to be assembled. However, the same extension sleeve 40 may. be nsedeven though various size clamps are provided.

In actual practice the clamp adapter blanks may be provided with spaced cable-grasping, arcuate surfaces for. engaging a cable having a diameter as small as 7 of an inch and as larg e as 3 inches. The maximum diameter cable which may be used would be governed by the diameter of axial port 44in end wall 45. i

It should, therefore, be

It is thus seen that the cable extension sleeve of the present invention will allow enough working space for a worker to strip suflicient insulation from the wires 12 in order to make the soldered connection with the pins 13, securely hold the cable on the electrical connector to prevent any damage or injury to the soldered electrical connections whereby any axial or longitudinal pull on the cable will be transmitted up and around through the sleeve body and not to the soldered connections, and most importantly eliminate the excessive expense of making and stocking a plurality of different size clamps for assembling different diameter cables to a standard size electric-a1 connector by the use of making the clamps with the standard, preformed, clamp adapter blanks as described hercinabove.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, invention may be practiced otherwise than as specifically described.

We claim:

1. In combination with a tubular extension sleeve having one open end provided with means for removably connecting the sleeve to a connector, the provision of: a pair of parallel, diametrically opposed, spaced integral supporting and guiding members extending outwardly from the opposite end of said tubular sleeve, each of said members being T-shaped in section, the arms of said members opposing each other and lying in spaced, parallel planes; and a pair of identical clamping bodies, each having a front face bounded by transverse, bottomed slots, and an ear at each end beyond each slot, each of said ears having a face parallel to the front face and in a plane between said front face and slot bottom; the said transverse slots being adapted to cooperatively and slidably contact the arms of said T-shaped members; aligned bores in said ears and T-shaped member to receive connecting means; and a bore having an axis parallel to and between said opposing front faces formed in both said clamping bodies to grasp and hold a cable.

2. In combination with an extension sleeve having one open end provided with means for removably connecting the sleeve to a connector, the provision of: a pair of spaced integral supporting and guiding members on the opposite end of said sleeve, each member having an arm spaced from and parallel to the other arm; a pair of identical clamping bodies, each having a front face bounded by transverse, bottomed slots being adapted to cooperatively and slidably contact said arms on the supporting guiding members; a bore in both of said clamping bodies having an axis parallel to and between said opposing faces to grasp and hold a cable; and connecting means for securing said clamping bodies on said members and for moving said clamping bodies toward and away from each other and into contact with said arms.

3. In combination with an extension sleeve having one open end provided with means for removably connecting the sleeve to a connector, the provision of: a pair of spaced, integral supporting and guiding members on the opposite end of said sleeve, and a pair of identical clamping bodies, each having a front face and spaced, transverse, bottomed slots being adapted to cooperatively and slidably contact said supporting and guiding members; a bore in both of said clamping bodies having an axis parallel to and between said opposing faces to grasp and hold a cable; and connecting means for securing said clamping bodies on said members and for moving said clamping bodies toward and away from each other and into sliding contact with said supporting and guiding members.

4. In combination with an extension sleeve having one open end provided with means for removably connecting the sleeve to a connector, the provision of: a pair of spaced, integral supporting and guiding members extending outwardly from the opposite end of said sleeve, each member having an arm spaced from and parallel to the other arm; a pair of clamping bodies, each having a front face bounded by transverse, bottomed slots, and an ear at each end beyond each slot, the transverse slots being adapted to cooperatively and slidably contact said arms of said supporting and guiding members; a bore in both of said clamping bodies having an axis parallel to and between said opposing faces to grasp and hold a cable; and connecting means for securing said clamping bodies on said members and for moving said clamping bodies toward and away from each other and into contact with said arms.

References Cited in the file of this patent UNITED STATES PATENTS 581,050 Wentz Apr. 20, 1897 861,828 Grindrod July 30, 1907 875,729 OBrien Jan. 7, 1908 1,923,462 Stoner Aug. 22, 1933 1,951,306 Johannsen Mar. 13, 1934 1,967,006 Eccles July 17, 1934 2,000,850 Knell May 7, 1935 2,258,365 Mills Oct. 7, 1941 2,480,895 Anderson Sept. 6, 1949 2,538,614 Austin Ian. 16, 1951 2,785,912 Risley et a1. Mar. 19, 1957 

